DSEG SEGMENT
    DATA1 DW 0F865H
    DATA2 DW 360CH
DSEG ENDS
;
ESEG SEGMENT
    SUM DW 2 DUP(?)
ESEG ENDS
;
CSEG SEGMENT
    ASSUME CS:CSEG,DS:DSEG,ES:ESEG
    START:MOV AX,DSEG
    MOV DS,AX
    MOV AX,ESEG
    MOV ES,AX
    MOV AX,DATA1
    ADD AX,DATA2
    MOV SUM,AX
    HLT
CSEG ENDS
    END START